Casing pusher



Feb. 24, 1959 FIG. 2

M. AQDANNEHL CASING PUSHER Filed Feb. 20, 1956 IN V EN TOR. MELVINAUG'US T DANNEHL ATTORNEY United States Patent() 1 Claim. (Cl. 254-29)This invention relates generally to improvements in the art of welldrilling, and more particularly, but not by way of limitation, to anapparatus for pushing cylindrical members such as casing and drill pipeinto a restricted well bore.

In geophysical prospecting it is frequently necessary to drill shotholes in areas where sand, gravel and boulders are encountered,particularly in the sedimentary portion of the shot holes. Such stratatend to cave in the walls of the bore hole, both while the bore is beingdrilled and in the process of loading dynamite in the hole. As a result,the usual procedure'is to set a casing through the sedimentary portionof such a shot hole or bore to facilitate drilling the bore below thesedimentary portion, and to prevent caving in of the walls of the borewhile the shot hole is being loaded with dynamite.

During the operation of lowering a casing through such a shot hole, thelower end of the casing frequently contacts a restricted portion of thebore where the walls of the bore have already caved in. In such an eventit is necessary to force the casing through the restricted portion ofthe bore. Various methods have heretofore been used to push the casingdownwardly. Perhaps the most efficient method heretofore known was bythe use of a jar hammer. This operation was accomplished by lifting alarge weight (such as 200 pounds) with the hoisting line of the drillingapparatus and then dropping the weight on top of the casing. It will beapparent that the only instant a substantial force is applied to thecasing by the use ofsuch a process is at the instant the weight contactsthe upper end of the casing. Therefore, such a method is slow andtedious and frequently resulted in failure; thereby necessitatingpulling the casing and starting over, or, if the bottom of the casingwas below the sedimentary formation, cutting off the casing toapproximately ground level.

The present invention contemplates a novel clamping apparatus wherebythe drive rod of the drilling unit, which is usually operated byhydraulic pressure, can be applied directly to the casing. The apparatusof this invention utilizes a pair of pivotally supported clamps forsecurely contacting opposite sides of the casing or other cylindricalmember, whereby a substantial downward force may be imposed through theclamps to the casing. The clamps are supported in such a manner that thedownward force may be applied to the casing with a minimum tendency forpivoting orbending the casing,

whereby the casing may be forced through a shot hole in a substantiallytrue vertical direction. Also, the apparatus of this invention may beeasily arranged along the casing by the hoisting line of the drillingunit for making a new bite or engagement with the casing to furtherforce the casing into a well bore or shot hole.

An important object of this invention is to generally improve welldrilling operations.

Another object of this invention is to facilitate the lowering of casingthrough a restricted shot hole or well bore.

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A further object of this invention is to impose the maximum availableforce on a casing being lowered through a restricted shot hole.

Another object of this invention is to minimize the bending of a casingbeing forced through a restricted shot hole, whereby the casing ispushed in the desired downward direction.

A still further object of this invention is to provide a simplyconstructed casing pushing apparatus which may be economicallymanufactured.

Other objects and advantages of the invention will be evident from thefollowing detailed description, when read in conjunction with theaccompanying drawings, which illustrate my invention.

In the drawings:

Figure 1 is a perspective view of my novel casing pusher.

Figure 2 is an elevational view of the casing pusher shown in operatingposition on a casing during a pushing operation.

Figure 3 is an elevational view of the casing pusher being raisedupwardly along a casing for the purpose of reengaging the casing andfurther pushing the easing into a well bore.

Broadly stated, the present invention may be defined as an apparatus fortransmitting a downward pushing force to a vertically extendingcylindrical member, comprising a pair of parallel side beams secured inspaced relation, a pair of opposed clamping jaws pivotally securedbetween and at one end portion of said beams, said jaws being spaced toreceive the cylindrical member therebetween and to clamp said memberwhen the opposite end portions of said beams are forced down withrespect tosaid jaws, and a push plate secured to said opposite endportions of said beams for receiving the downward pushing force, saidpush plate being secured at an angle to remain substantially horizontalwhen said jaws engage the cylindrical member.

Referring to the drawings in detail, and particularly Fig. 1, referencecharacter 4 generally designates my novel casing pusher which has a pairof parallel side beams 6. The side beams 6 are arranged in spacedrelation to receive and support a pair of opposed clamping jaws 8 and 10therebetween.

a The foremost or forward clamping jaw 8 is rigidly secured on a pair ofarms 12 which extend forwardly from the jaw along the adjacent or innersides of the beams 6 toward the ends 14 thereof. A pin 16 extendstransversely through the arms 12 and the side beams 6 adjacent the ends14 to pivotally support the arms 12 and the forward jaw 8. The pin 16has a handlelS on one end thereof to facilitate removal of the pin. Theopposite end of the pin 16 may be supported in any desired manner in theopposite side beam 6, such as by the use of a threaded nut or cotter pin(not shown).

The opposite clamping jaw 10 is rigidly supported on a pair of arms 20which extend rearwardly from the jaw along the side beams 6. Another pin22 extends transversely through the side beams 6 to pivotally supportthe arms 20. Thepin 22 is preferably permanently secured to the sidebeams 6, and in spaced relation to the pin 16, to position the clampingjaws 8 and 10 loosely around a casing or the like when the arms 12 and20 extend horizontally along the side beams 6 as illustrated in Figurel, and as will be more fully hereinafter set forth. A hook or eye 24 issecured to the upper surface or crown of the pin 22 about half waybetween the beams 6 for receiving a hoisting line 34 of the drillingunit (not shown) to facilitate raising the apparatus 4.

A push plate 26, preferably in the form of a channel, is secured betweenthe side beams 6 rearwardly of the pin 22 and extends beyond the rearends 28 of the side beams 6. It is to be observed that the push plate 26extends Patented F eh. 24, 1959 Operation In lowering .a casing- 30(see'Fig. 2') through a typical well bore or shot hole 32, the casing 36will frequently contact'a restricted portion (not shown) of the wellbore 32;, whereupon the casing 36} will not move downwardly through thewell, bore 32 by its own weight. In that event, the casing pusher 4 maybe installed on the casing 30 in the manner illustrated in'Fig. 2 totransmit a downward, force-from the drilling apparatus to the casing 36.

To install the apparatus 48 on the casing 3t}, the forward pin 16 isremoved from the side beams 6 to permit removal of the forward clampingjaw 5; and arms 12. The side: beams 6 may thenbe placed transversely or.laterally over the casing 30 until the rearward clamping jaw it)contacts the side of the casing. whereupon the clamping jaw 8' is placedin contact with the opposite side of the casing 30 and is securedbetween the side beams 6 by reinserting the pin 16. It is preferred thatthe clamping jaws 8 and 10 are of a size-and the pins 16 and 22 arespaced-such that the clamping'jaws 8 and lit loosely surround the'casing30 when the side beams 6 extend at right angles to the casing 39.

The usual drive rod (not shown) of the drilling apparatus is thenlowered into contact with the push plate 2.6 to pivot the side beams 6into the position illustrated in Fig, 2. As the side beams 6 are pivotedto lower the rearward ends 23 thereof, the clamping jaws 8 and it? arewedged or forced into contact with the opposite sides of the casing 30.his preferred that the size of the clamping jaws 8 and to, with respectto the casing 36:, is such thattlre push plate 26 extends substantiallyhorizontal when the". clamping jawsare in tight engagement with theopposite sides of the casing. Therefore, when the downward force on thepush plate 26 is continued, the driverod will exert a verticallydownward force on. the push plate 26'and will not have a tendency towedge the apparatus 4 toward the casing 3%. Also, the downward forceexerted by the drive rod will have a minimum tendency to bend the casing3%, thereby efiectively trans mitting the downward force of the drillingunit to the casing 30.

Whenthe apparatus' 4 has been forced downwardly into proximity with theground level, or to the lowest extent desired, the hoisting line 34 ofthe drilling apparatus is secured to the eye or hook 24 and the drillrod is raised above the push plate 26. The hoisting line 34 is thenpulled upwardly to rais'e the apparatus along the casing 30. It will beobserved that the eye 24 is positioned at approximately the center ofgravity ofthc apparatus-4, whereby the side beams 6 will tend to pivotback into a horizontal position when an upward force is exerted on thehoisting line'34.

As thebeam's 6 are moved into their horizontal positions, the clampingjaws 8 and 10 pivot on the pins 16 and 22 until the arms 12 and 26extend horizontally along the side beams 6. The jaws 8 and 10 will thenagain extend loosely around the casing 30 and slide along the casing 30as the apparatus 4 is raised In the event a further pushing of thecasing 36 is de sired or required, the hoisting line 34 is stopped whenthe apparatus 4 has beenraised tothe desired extent. The drive rod isthen again lowered into contact with the push" plate 26 tolpivot theside beams 67 and lower the ends 28, to again bring the clamping jaws 8and 10 into engagement with opposite sides of the casing 30. The

hoisting line 34 is then disconnected from the eye 24, or slackened, andthe force imposed by the drive rod on the plate 26 is continuedto againforce the casing downwardly in the well bore 32;

The action of the apparatus 'may be supplemented by periodicallydropping a weight on the upper end of t thecasiug 30 in the'mauner'previously described. How'- ever, theuse of the apparatus 4 alone'is allthat is ordinarily required to force the casing 30 into the well'bore32.

The apparatus 4 may. be-rernoved'. from the casingSt) either by raisingthe apparatus 4 until it slips off of the upper end of the casing, orby"re"m'oving the forward jaw 8 in the manner previously described andmoving the apparatus 4 laterally from the casing. It will be apparentthat'the; apparatus 4'111'2Yib8' used on various sizes ofcasing ortother cylindrical members merely by? u changing the sizes of theclamping jaws 8 and 10.

From'the foregoing it is apparent that the present in vention willimprove well drilling operations-and panic ularly the completion of shotholes for geophysicalpr'ospecting. By use of the presentinvention, thelowering:

of casing through a' restricted shot hole or well bore will bematerially facilitated, since the maximum available force may be imposedupon the casing. The'casingwill he forced in substantially a truedownward dircction with a minimum of bending of the casing. Itwilltalsotbe apparent that the present apparatus is simply constructed?and may be economically manufactured Changes may be made in thecombination and arrange ments of parts as heretofore set forth inthesp'ecificatio'rr andshownin the drawings, it being understood tliatchanges may be made in the precise-embodiment shown without departingfrom the spirit and scopeof the inventtion as settfortn in the followingclaim:

I claim:

' An apparatus for transmitting a downward pushing force to a verticallyextending cylindrical member, comprising a pair" of parallel sidebeamssecured in spacedz relationship, apair of opposed arcuate clampingjaws, a" pair of parallel spaced arms for each of said jaws, eacharmbeing secured at one end to one of said jaws,',aipairlof pins,extendingv transversely through said beams,*one.

pin extending through one end of each pair ofsaid arms to pivotallysecure said pair of clamping jaws to said pair of parallel beams; a pushplate secured to said beams externally of said jaws for receivingadownward pushing force, said push platebeing secured at an angletoremain substantially horizontal when said jawsengagethe'cylindricalme'moer, one'of saidpair of pins being removable and securing the outerjaw of-said pair of clamping jaws between said side beams, and a liftinghook secured to the other of said pair of pins for raising the apparatusalong the cylindrical member.

References Cited in the file ofthis patent UNITED STATES PATENTS1,469,911 Aumiller t. i Oct. 9, 1923;

2,679,379 Peterson 7... May 25,- 1954' FOREIGN PATENTS 329,923- Germany"Dec'. 1; 1920'

